An Efficient Method for Computing the Power Potential of Bypass Hydropower Installations

Small-scale hydropower installations make possible a transition towards decentralized electrical power production with very low ecological footprint. However, the prediction of their power potential is difficult, because the incoming flow velocity and the inlet and outlet water heights are often outside of the control of the operator. This leads to a need for a method capable of calculating an installation's power potential and efficiency rapidly, in order to cover for many possible load cases. In this article, the use of a previously-published theoretical framework is demonstrated with the case of a mid-scale hydropower device, a 26 m long water vortex power plant. It is shown that a simplified CFD simulation with a single output (the mass flow rate) is sufficient to obtain values for the two coefficients in the model. Once this is done, it becomes possible to evaluate the device's real-life performance, benchmarking it against reference values anchored in physical principles. The method can be used to provide design guidance and rapidly compare different load cases, providing answers that are not easily obtained using intuition or even experiments. These results are obtained for a computing cost several orders of magnitude smaller than those associated with a full description of the flow using CFD methods.